The present invention relates to the single crystal of GaAs semiconductor as well as a method of producing the same, and a semiconductor device utilizing the GaAs single crystal. In particular, the present invention is well suited to make uniform the characteristics of semiconductor elements which are fabricated in a wafer of GaAs semiconductor.
Among factors which dominate the dispersion of semiconductor elements fabricated in a wafer, those attributed to a crystal structure such as resistivity and FET characteristics have heretofore been considered to be the distribution of etch pit densities and the ununiform distribution of an impurity substance within the wafer, but they have not been clarified yet. Reports on them having hitherto been made include the following:
(1): Yoshizumi TSUNODA, Masayoshi MATSUI and Takeshi YOKOYAMA PA1 (2): Yasunobu ISHII, Shintaro MIYAZAWA, Akira ISHIDA and Hajime YAMASAKI PA1 (3): Yoshiro HIRAYAMA, Shintaro MIYAZAWA and Hajime YAMASAKI PA1 (where d.sub.o denotes the lattice constant of a GaAs single crystal of its stoichiometric composition at the normal temperature (23.+-.1.degree. C.), D=.DELTA.d.sub.max -.DELTA.d.sub.min holds with .DELTA.d.sub.max being the maximum value of .DELTA.d in the wafer and .DELTA.d.sub.min being the minimum value of .DELTA.d in the wafer, and .DELTA.d=(d-d.sub.o) holds in which d denotes the lattice constant of the GaAs wafer at the normal temperature).
Collection of Drafts of Lectures in 30th Spring Symposium of Applied Physics Society (1983), 4p-D-10, p. 437 PA2 Collection of Drafts of Lectures in 31st Spring Symposium of Applied Physics Society (1984), 1p-D-5, p. 633 PA2 Collection of Drafts of Lectures in 31st Spring Symposium of Applied Physics Society (1984), 1p-D-6, p. 633